May 13, 2016
Do Women Need to Exercise More Than Men to Achieve the Same Fitness Level?
May 16, 2016
Do women have to train with higher volume to experience the same benefits as men who train less? It’s an interesting question. We know that women have less testosterone and human growth hormone (HGH) in their bodies, which is why men have the capacity to build bigger, stronger muscles. A man’s skeletal frame is also bigger to support larger muscle mass. But women have more estrogen in their systems than men (estrogen is an anti-catabolic hormone that helps with muscle repair and reduces protein break-down during exercise). They also have proportionally larger type I fibers (slow-twitch) than men. Slow-twitch fibers are resistant to fatigue, so people with a greater number of these types of fibers are well suited for endurance activities. Type II fibers are fast-twitch—they fatigue quickly but are used in powerful bursts for movements like sprinting or jumping. Though men and women each have advantages when it comes to getting fit, is it fair to say that women must train more to reap the same fitness level as men?
Two separate studies suggest that may be the case. A study from Emory University, ‘Physical fitness in relation to amount of physical exercise, body image, and locus of control among college men and women’, had 243 freshmen estimate the amount of time they spent exercising over the course of three months. These exercises included ‘brisk walking, jogging aerobics, and sports activities like soccer, tennis, and swimming.’ The study associated increased fitness with ‘increased amounts of exercise, internal locus of control, and good body image.’ The results of the study showed a statistically significant interaction between sex and amount of exercise. “There was a statistically significant interaction between sex and amount of exercise. For students who exercised 2-4.9 hours per week, men were more fit than women. Fitness was comparable for men and women exercising less than two hours or at least five hours per week. Women had to exercise 5 or more hours weekly to achieve the fitness level of men who exercised 2 to 4.9 hours per week.”
Of course their definition of fitness is far less complete than the one we recognize in CrossFit (increased work capacity across broad time and modal domains). There are no true strength or gymnastic tests in the study, and students had to estimate the amount of time they spent exercising.
Despite the obvious failings in the Emory study, a separate study from the University of Missouri suggests that women must do more to reap the same positive health outcomes as men. The study, from 2013, utilized a 16-week aerobic walking program to test the heart rate and blood pressure of 22 obese men and women with Type 2 diabetes. The individuals also completed an isometric handgrip test (they continually squeezed an object for several minutes) at the beginning and the end of the program. “Our results indicate gender may contribute to differences in cardiovascular function of obese individuals with Type 2 diabetes,” said Jill Kanaley, a professor in the Department of Nutrition and Exercise Physiology at MU. “Men saw improvement after aerobic exercise training, but the women did not experience the same benefits.”
One of the key reasons that men have greater success with losing weight than women, even if the two are on the same training program, is due to body composition. Men have a higher proportion of muscle mass in their bodies than women, and muscle is more metabolically active than fat. At rest, muscle is three times more metabolically active than fat, meaning it burns three times the calories; Hence why men will lose more fat than women following a similar dietary and exercise program.
But that’s not to say that women don’t hold training advantages over men. Having more type I fibers and estrogen, combined with their increased use of body fat as an energy source during exercise, means that women are more suited to train at higher volumes and for greater duration than men. A study from the European Journal of Applied Physiology and Occupational Physiology found that the endurance capacity of women is greater than that of men in both isometric (muscle length doesn’t change as it contracts) and dynamic muscular exercise when the work load is relatively low (at loads that are 50, 60, and 70% of the individuals one-rep max). For a more recent example, consider the performance of Sam Briggs during event 3 of the 2015 CrossFit Games—Murph. Athletes had to complete a 1-mile run, followed by 100 pull-ups, 200 push-ups, 300 air squats, and another mile run—all while wearing a 20/14lb vest. Briggs won the event for the women in a time of 39:10, a score that would have placed her 2nd overall in the men’s event.
While men do hold certain physical advantages over women that make it easier for them to build muscle and train more explosively, women hold distinct training advantages over men, too. Granted, while they may need to train longer and harder to develop the same levels of strength and fat loss (relatively speaking), they can match and even surpass their male counterparts in endurance training and training volume.
Photo courtesy of Aryan Barto/2015 CrossFit Open Photo Submissions